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  2. Opal - Wikipedia

    en.wikipedia.org/wiki/Opal

    Opal occurs in significant quantity and variety in central Mexico, where mining and production first originated in the state of Querétaro. In this region the opal deposits are located mainly in the mountain ranges of three municipalities: Colón, Tequisquiapan, and Ezequiel Montes. During the 1960s through to the mid-1970s, the Querétaro ...

  3. Caliche - Wikipedia

    en.wikipedia.org/wiki/Caliche

    In northern Chile and Peru, caliche also refers to mineral deposits that include nitrate salts. [4] [5] Caliche can also refer to various claylike deposits in Mexico and Colombia. In addition, it has been used to describe some forms of quartzite, bauxite, kaolinite, laterite, chalcedony, opal, and soda niter.

  4. Ammolite - Wikipedia

    en.wikipedia.org/wiki/Ammolite

    Ammolite is an opal-like organic gemstone found primarily along the eastern slopes of the Rocky Mountains of North America.It is commonly unearthed by natural erosion or through the process of various mining practices, within the perimeter of an ancient sea bed called the Western Interior Seaway. [2]

  5. Channel-iron deposits - Wikipedia

    en.wikipedia.org/wiki/Channel-iron_deposits

    Channel iron deposits are an important source of iron ore, with the deposits at Yandi and Robe River accounting for approximately 47% of iron ore mined from the Hamerley Iron province. Although channel iron deposits are typically low-grade at 53% to 57% Fe in-situ, they are composed of goethite-limonite which are hydrated iron oxide species.

  6. Cave of the Crystals - Wikipedia

    en.wikipedia.org/wiki/Cave_of_the_Crystals

    Giant Crystal Cave was discovered in April 2000 by miners excavating a new tunnel for the Industrias Peñoles mining company located in Naica, Mexico, [9] while drilling through the Naica fault, which they were concerned would flood the mine. [10] The mining complex in Naica contains substantial deposits of silver, zinc and lead.

  7. Biogenic silica - Wikipedia

    en.wikipedia.org/wiki/Biogenic_silica

    Biogenic silica (bSi), also referred to as opal, biogenic opal, or amorphous opaline silica, forms one of the most widespread biogenic minerals. For example, microscopic particles of silica called phytoliths can be found in grasses and other plants. Silica is an amorphous metalloid oxide formed by complex inorganic polymerization processes.

  8. Peñasquito Mine - Wikipedia

    en.wikipedia.org/wiki/Peñasquito_Mine

    The exploration was suspended in 1997 but resumed in 2002 when Western Silver took over. A significant polymetallic deposit was discovered in 2006 and construction of the mine began in 2007, the first concentrates were produced in October 2009, and commercial production began in 2010. [4]

  9. Mexican Geological Survey - Wikipedia

    en.wikipedia.org/wiki/Mexican_Geological_Survey

    The Mexican Geological Survey originated as the Directing Committee for Mexican Mineral Resource Research, established in 1944, which published bulletins on the exploration of mineral deposits. In 1949, the organization changed its name to the National Research Institute for Mineral Resources, and in 1955 it became the Non-Renewable Natural ...